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View Full Version : BMC's Challenger R/T is Blown-up




BMC Performance
03-23-2009, 09:45 PM
Well, I never expected to be writing a thread like this, at least not so soon in the ownership of my Challenger, but ... my motor is blown. Since I've shared with you all the exciting details of modifying this car so far, I figured you should know the less pleasing results as well.

I have around 6,600 miles on my Challenger R/T, and approximately 1,600 with the Techco supercharger. My car was the test car for Diablo's tuning updates for the new 5.7 engine and Johan tuned my car on the dyno several times, including almost a full day when we put the supercharger on with road datalogging also.

I took my car to the track Friday for the first time since we put the supercharger on, and the first pass took it a bit cautiously and ran a 11.9 ET. I took the second run more aggressively and felt like the run would be a couple a tenths quicker. Toward the top end of the track, my car hit the 3-4 shift and stuttered a tad, but I stayed in it and ran another 11.9 ET. As I slowed the car down, the check engine light came on. When I stopped for the time slip, the car idled really rough and I knew there was a problem. Back in the pits I check the code(s) and had a 300 Random Misfire and 301 Cylinder 1 Misfire. Without any tools there, I decided to limp the car back to the shop ... but only after rooting on Frank as he ran his Techco supercharged 300C into the 12's ... on air bags!!

Back at the shop late Friday night, I pulled the plugs and both from cylinder 1 had been crunched, with the straps collapsed and clear scratches as well. All the other plugs were still gapped properly. Here are the plugs from cylinder 1.

http://gallery.me.com/bmcperformance/100434/DSC00894/web.jpg?ver=12376660390001

http://gallery.me.com/bmcperformance/100434/DSC00895/web.jpg?ver=12376660460001

http://gallery.me.com/bmcperformance/100434/DSC00898/web.jpg?ver=12376660090001


I was planning to bore scope it today and decided to leave the car until then and enjoy the weekend. About 8:30 Sunday night I couldn't stand it any longer and went to the shop to remove the valve cover and check things out. I could then see down through the spark plug hole and tell that there were marks on the piston from the spark plugs. Knowing what this meant, I decided to go ahead and remove the Techco supercharger and driver's side head to see how bad it was. Here are some pics of what we found ...

Cylinder 1 Piston:
http://gallery.me.com/bmcperformance/100442/DSC00911/web.jpg?ver=12378127580001

Cylinder 1 Valves:
http://gallery.me.com/bmcperformance/100442/DSC00905/web.jpg?ver=12378127500001


So, today we pulled the motor and it's sitting aside, with my car as a roller until I decide what to do. I had always wanted to just forge and keep a 5.7L / 345ci displacement (like factory) but now that this has sprung up suddenly, I want to plan out the best course for what I do with the car. I have spoken with Carlos at Techco at length and will know something for sure tomorrow on some options, but we're probably going to go with a Techco 392 short block.

As an aside, I want to say a big personal thank you to Carlos. When I told him the motor blew at the track, the first thing he asked was if I was okay. Knowing the danger of drag racing, his first concern was for me, and my safety and that means more to me than anything. We all have a choice to make in improving the performance of our vehicles and I will continue to support Techco and Carlos!!

I will keep you all posted in this thread, and am already missing my baby!!




SRT8U
03-23-2009, 09:52 PM
The Trials and Tribulations of doing R&D :)
Well on the bright side looks like we will be setting some more Chally record's soon!

wickedchargerrt
03-23-2009, 09:57 PM
Is there a cause figured out yet? Forget fixing til ya know what happened.
Did it lean out? certainly you would have heard a knock prior to that much piston going flying? I really cant think of much else other than a lean condition that could have squashed that piston. Sucks that it happened to you guys. I'm truly sorry. Much worse people i'd wish this on instead of you guys. :sad:
We expect a full write up on this rebuild though, with pics :grin: Time for low compression pistons for that blower.

bigjim.srt-8
03-23-2009, 09:58 PM
Thats tough luck..... sounds like she was running fast before it blew. good luck on the next build up....

BigBlackRT08
03-23-2009, 10:00 PM
Glad it wasn't worse, Still stinks though.

SRT8U
03-23-2009, 10:03 PM
Is there a cause figured out yet? Forget fixing til ya know what happened.
Did it lean out? certainly you would have heard a knock prior to that much piston going flying? I really cant think of much else other than a lean condition that could have squashed that piston. Sucks that it happened to you guys. I'm truly sorry. Much worse people i'd wish this on instead of you guys. :sad:
We expect a full write up on this rebuild though, with pics :grin: Time for low compression pistons for that blower.

Yeah I know Lisa will be looking for some nice Dishy Psitons hehe!

wickedchargerrt
03-23-2009, 10:04 PM
Makes me wonder if total seal has rings for us out yet? ? ? hmmmmmmm

charger08srt
03-23-2009, 10:40 PM
sorry to see that... hope you get back on the road soon:beerchug:

TheBigAndy
03-23-2009, 11:13 PM
Man that sucks, but i guess its the price you pay to play.